With the advancement of computers, digital holography has become an area of interest and has gained popularity. Research findings derived from this technology can enable digital holograms to be captured optically or generated numerically, and to be displayed with holographic display devices such as a liquid crystal on silicon (LCoS) display device or a spatial light modulator (SLM) display device. Holograms generated in this manner can be in the form of numerical data that can be recorded, transmitted, and processed using digital techniques. On top of that, the availability of high capacity digital storage and wide-band communication technologies also lead to the emergence of real-time video holography, casting light on the future of, for example, a three-dimensional (3-D) television system.
A Fresnel hologram of a 3-D scene can be generated numerically by computing the fringe patterns emerged from each object point to the hologram plane. The Fresnel hologram of the 3-D scene can be used to reconstruct and display 3-D holographic images that can recreate or represent the original 3-D scene from various visual perspectives (e.g., various viewing angles).
A hologram can have a number of advantages. For instance, a hologram can present a true 3-D view of an object scene (e.g., commonly referred to as a reconstructed image) to observers. Also, the reconstructed image can be directly projected onto a display screen without the need of focusing lens. Further, a hologram can be resistant to damage and noise contamination.
A hologram is often considered to be the ultimate solution to 3-D display, as it can record the complex wavefront emitted from a 3-D object scene. A complex hologram can reproduce desirable (e.g., excellent quality) 3-D images that can be free from the unwanted images that can be present in other types of holograms (e.g., amplitude). A desirable scenario can be displaying the complex hologram with a single complex device, employing illumination with a coherent light source (e.g., a light-emitting diode (LED) source).
However, in reality, a conventional system for displaying a complex hologram can have some drawbacks. Since a complex hologram is a complex image, optical integration of a pair of displays to present the real and imaginary components of the complex image, or other pair of orthogonal components, such as magnitude and phase, can be required. Also, due to the fine resolution of a holographic display, precise alignment of a pair of displays can be a significant issue, and can be difficult to achieve in practice. As a result, a display system for displaying complex holograms can be expensive and difficult to construct.
The above-described description is merely intended to provide a contextual overview relating to digital holograms, and is not intended to be exhaustive.